2121012709 has 2 divisors, whose sum is σ = 2121012710. Its totient is φ = 2121012708.

The previous prime is 2121012683. The next prime is 2121012713. The reversal of 2121012709 is 9072101212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1301622084 + 819390625 = 36078^2 + 28625^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121012709 - 2⁷ = 2121012581 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121012809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060506354 + 1060506355.

It is an arithmetic number, because the mean of its divisors is an integer number (1060506355).

Almost surely, 2^2121012709 is an apocalyptic number.

It is an amenable number.

2121012709 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121012709 is an equidigital number, since it uses as much as digits as its factorization.

2121012709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 2121012709 is about 46054.4537368537. The cubic root of 2121012709 is about 1284.8361783011.

The spelling of 2121012709 in words is "two billion, one hundred twenty-one million, twelve thousand, seven hundred nine".